Respuesta :
Step-by-step explanation:
1. Given : P = $1200 , R = 5%, T = 7 years
Therefore, the simple interest is, [tex]$SI = \frac{PTR}{100}$[/tex]
[tex]$=\frac{1200 \times 7 \times 5}{100}$[/tex]
= $ 420
Therefore, total amount Manny will have is A = P + Si
= 1200 +420
= $ 1620
2. Given : P = $1200 , r = 5%, t = 7 years, n = 12 times (compounded)
So the amount is :
[tex]A=P\left(1+\frac{r}{n}\right)^{nt}[/tex]
[tex]A=1200\left(1+\frac{0.05}{12}\right)^{12\times 7}[/tex]
= 1692.17
So Manny would have approximately $ 1692 when compounded monthly.
3. Given :
The amount of stock = $ 100
rate of depreciation = 3%
Time = 20 years.
Therefore, using compound interest, we get
Future value = initial value x [tex]$(1-\text{rate})^{number of years}$[/tex]
= [tex]$100 \times (1 - 3 \%)^{20}$[/tex]
= 54.38
So after 20 years, the value would be $ 54.38
4. Given :
Initial amount, i = 40 gram
time, t = 40 days
half life of the isotope, h = 8 days
1/2 is used because of half life
Therefore, the final amount is given by :
[tex]$a=i \times \left(\frac{1}{2}\right)^{t/h}$[/tex]
[tex]$a=40\times \left(\frac{1}{2}\right)^{40/8}$[/tex]
= 1.25 gram
So after 40 days, 1.25 gram will be left.
5. Let p = pizza and d = drink
So according to the question,
2p + 4d = $ 15 ....(i)
4p + 7d = $ 30...(ii)
Equation equation (i) and (ii), we get
d = $0
and p = $ 7.5